Answer:

The enthalpy of an ionic compound is determined by several factors, including lattice energy, ionization energy, and electron affinity. However, in some cases, the lattice energy is the primary factor responsible for the negative enthalpy of the compound. One such example is given below.

Sodium Chloride (NaCl)

Lattice energy is the energy released when oppositely charged ions are brought together to form a solid crystal lattice structure. In the case of sodium chloride (NaCl), the lattice energy is the primary factor responsible for the negative enthalpy of the compound.

Explanation:

Sodium chloride is an ionic compound that consists of positively charged sodium ions (Na+) and negatively charged chloride ions (Cl-). The lattice energy of NaCl is negative because energy is released when the ions come together to form a crystal lattice structure.

This is because when Na+ and Cl- ions come together, the attractive forces between them are stronger than the repulsive forces. As a result, the ions are held together in a stable crystal lattice structure, and energy is released in the process. This energy is the lattice energy of NaCl.

The lattice energy of NaCl is very high because the ions are held together by strong electrostatic forces. This makes NaCl a very stable compound with a high melting and boiling point.

In conclusion, the negative enthalpy of NaCl is primarily due to its high lattice energy, which is the energy released when the oppositely charged ions form a stable crystal lattice structure.